1. Field of the Invention
The present invention relates to a light source device. More specifically, the present invention relates to a light source device used in an optical equipment such as a projector using a light beam irradiated by a light source, the light source device capable of efficiently cooling a light source lamp housed therein by introducing an air from a fan provided on the optical equipment.
2. Description of Related Art
Conventionally, projectors have been used for presentation at conferences, academic societies, exhibitions, movie-viewing at home and the like. Such projectors modulate a light beam irradiated by a light source provided inside an exterior case in accordance with image information to form an optical image and projects the optical image in an enlarged manner. In recent projectors, in order to clearly display the projected optical image, it is required to increase the illuminance of light source lamps.
High-pressure mercury lamps, metal halide lamps and the like are used as the light source lamp of such projectors, which are consumable supplies and are required to be exchanged while using optical equipments such as projectors using the lamps. Further, light-emitting tube made of quartz glass etc. may be exploded according to life span of the lamps and broken pieces thereof may be scattered inside the projector. Furthermore, since a great amount of heat is generated by the light source lamp in accordance with the increase in the luminance thereof, in order to prevent the explosion of the light source lamp, the generated heat has to be radiated to the outside to cool the lamp.
In light of the above, following mechanism is provided in a conventional light source device having a light source lamp (see Japanese Patent Laid-Open Publication No. 2002-107823, for instance). A light-irradiation side of a reflector is covered with a transparent plate made of glass etc. and a plurality of air vents as intake and exhaust ports are formed on a part of the reflector or the transparent plate. Lid components (shutter components) are provided on the respective air vents so that the respective lid components open the air vents when the light source device is attached to the projector and close the corresponding air vents when the light source device is detached from the projector. According to the above arrangement, the light source lamp can be cooled and the broken pieces are not scattered around when the lamp is exploded, where the light source lamp can be exchanged together with the light source device.
However, according to the above arrangement where the air vents are closed by the lid components, since a space for opening and closing the lids have to be secured, a discharge hole of a lamp-cooling fan inside the projector cannot be directly connected with the opening, so that a part of the air outflowed from the discharge hole of the fan is leaked to the other section and the cooling ability of the fan cannot be fully exerted.